The field of the invention relates to multiple sampling devices for obtaining blood samples from a patient, and methods for their manufacture.
Multiple sampling devices have been used to advantage where one wishes to take a plurality of blood samples from a patient without risk of either backflow or spillage. Such devices often include a plastic needle hub having a chamber therein, an intravenous cannula attached to one end of the hub, a second cannula attached to the other end of the hub, and a one-way elastomeric valve positioned within the chamber. Two particularly advantageous assemblies are described in commonly assigned Ser. Nos. 915,670 and 915,671, both filed June 15, 1978. U.S. Pat. Nos. 3,817,240 and 3,874,367 are further examples of needle assemblies which are now known to the art.
According to present techniques for manufactuing needle assemblies, first and second polymeric hub assemblies are molded. An elastomeric valve is positioned upon receiving means on one hub, and the two hubs may thereafter be joined by conventional methods. Cannulas may be secured to the respective hub assemblies so that a fluid may flow from one cannula, through the valve within the hub assembly, and out through the other cannula. Epoxy may be used for attaching the cannulas to the hub assemblies either before or after they are joined.